<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../js1/demo.js"></script>
</head>

<body>
    <!--表单的JS操作-->
    <!-- 提交数据是键值对，之间用&连接 -->
    <form method="get" accept="">
        <input id="username" type="text" name="username" placeholder="请输入用户名">
        <br>

        <!-- 复选框 -->
        <input id="male" type="checkbox">男
        <input id="female" type="checkbox">女
        <br>


        <!-- 下拉框 -->
        <select id="city">
            <option value="1">杭州</option>
            <option value="2">上海</option>
            <option value="3">北京</option>
        </select>
        <br>

        <button type="submit">提交</button>
    </form>
</body>

</html>